1. Field of the Invention
The present invention relates to an in-finder display device used to identify the selected one of a plurality of areas in the subject field of a viewfinder.
2. Description of Related Art
Cameras in which one of a plurality of distance measurement areas in the subject field is selected and the photography lens is focused based on the distance measurement information of that selected area are known. With this type of camera, it is necessary to display the selected distance measurement area in the viewfinder. Conventionally, an in-finder display device has been provided to selectively display a mark corresponding to each one of the plurality of distance measurement areas on the viewfinder screen when the subject light is formed into an image. The mark corresponding to the selected distance measurement area displayed in the viewfinder screen overlays the subject image. This type of in-finder display device includes devices that use light-darkening display elements (such as, for example, liquid crystals and electrochromics or similar elements that create black displays on the viewfinder screen by blocking part of the subject light) and devices that use light-emitting display elements (such as LEDs or similar elements that create displays through light illumination).
However, because the light-darkening display elements are normally provided on the viewfinder screen, when an interchangeable viewfinder that does not have the light-darkening display elements is mounted on a camera in which the display of distance measurement areas is performed by light-darkening display elements, it becomes impossible to display the distance measurement areas in the viewfinder. If all interchangeable viewfinders were provided with light-darkening display devices, this problem could be resolved, but this would lead to an increase in cost for interchangeable viewfinders. In addition, light-darkening displays are difficult to see in dark subject fields (for example, during indoor or night photography). Furthermore, the responsiveness of a device that uses liquid crystal elements as the light darkening display is poor at low temperatures.
On the other hand, light-emitting displays that use light-emitting display elements are difficult to see in bright subject fields, and because the display light and the subject image on the viewfinder screen overlap, creating the image can be troublesome.